Dear Dave, Thankyou very much. With your outlined approach hopefully, I would get through. Thanks once again. Elisa
> From: lor...@usgs.gov > Date: Fri, 17 Jan 2014 08:52:38 -0600 > To: r-help@r-project.org > Subject: Re: [R] predefined area under the curve > > Elisa, > Part of the issue is that there is no unique solution. You could increase > each of the 6 values by a fixed amount to make up the 0.242003 difference > in area, or you could increase them proportionally, among many other > schemes. > I'll outline an approach and you can decide how you want to proceed. > 1. Determine the contribution of reach point to the total area: > matrix(diff(c(el[1,1], el[,1], el[12,1]), 2)/2) > 2. The total contribution from the last 7 values is 1.42607687227. > 3. To distribute the change equally over the last 7 values, simply add > 0.242003/1.42607687227 = 0.1696984 to each of those 12 values. > 4. To distribute unequally, you'll need to work that out yourself, but > knowing the relative weights will be the key. > Dave > > > >Date: Thu, 16 Jan 2014 13:24:41 +0000 > >From: eliza botto <eliza_bo...@hotmail.com> > >To: "r-help@r-project.org" <r-help@r-project.org> > >Subject: [R] predefined area under the curve > >Message-ID: <blu170-w1360c9aa25d48d8a388cbc689...@phx.gbl> > >Content-Type: text/plain > > > >Dear UseRs of R, > >My sincere apologizes in advance if my question isn't relevant to the > >operations in R. I actually have the following two columns data, with 12 > >rows in it. > > dput(el) > > > >structure(c(-1.42607687227285, -1.0200762327862, -0.736315917376129, > > -0.502402223373355, -0.293381232121193, -0.0965586152896391, > > 0.0965586152896391, 0.293381232121194, 0.502402223373355, > >0.73631591737613, 1.0200762327862, 1.42607687227285, > >1.99095972340185, 1.84006682649012, 1.71563586990498, > >1.60312301737773, 0.748443534297919, 0.696909774793038, > >0.64586377528834, 0.594330015783459, 0.270606020696256, > >0.242477807564444, 0.211370068418158, 0.173646844190226), .Dim = > >c(12L, 2L), .Dimnames = list( NULL, c("", "GG"))) > > > >When I plot column 2 against column 1 , i get a curve with an area > >[auc(column1,column2)] under it equals to 2.602997. As i am calibrating it > >for further simulations therefore i know that the area under the curve > should > >actually be equal to 2.845. I also know that the first 6 rows have been > >located accurately, therefore the rows from 7 to 12 need to be relocated > in > >such a manner that area under the curve gets equal to or as close as > >possible to 2.845. How can I do that? i have been doing it manually but at > >the cost of time and accuracy. > > > >Thankyou very much in advance. > >Elisa > > [[alternative HTML version deleted]] > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.